Unlike culture-sensitive data, which is subject to change by user customization or by updates to the .NET Framework or the operating system, invariant culture data is stable over time and across installed cultures and cannot be customized by users. This makes the invariant culture particularly useful for operations that require culture-independent results, such as formatting and parsing operations that persist formatted data, or sorting and ordering operations that require that data be displayed in a fixed order regardless of culture.

Persisting Data

The CultureInfo.InvariantCulture property can be used to persist data in a culture-independent format. This provides a known format that does not change and that can be used to serialize and deserialize data across cultures. After the data is deserialized, it can be formatted appropriately based on the cultural conventions of the current user.

The following example uses the invariant culture to persist a DateTime value as a string. It then parses the string and displays its value by using the formatting conventions of the French (France) and German (Germany) cultures.

code reference: System.Globalization.CultureInfo.InvariantCulture#1

Security Decisions

If you are making a security decision (such as whether to allow access to a system resource) based on the result of a string comparison or a case change, you should not use the invariant culture. Instead, you should perform a case-sensitive or case-insensitive ordinal comparison by calling a method that includes a StringComparison parameter and supplying either StringComparison.Ordinal or StringComparison.OrdinalIgnoreCase as an argument. Code that performs culture-sensitive string operations can cause security vulnerabilities if the current culture is changed or if the culture on the computer that is running the code differs from the culture that is used to test the code. In contrast, an ordinal comparison depends solely on the binary value of the compared characters.